One of the main complaints aimed at the last-minute rule changes in MotoGP is that they made it impossible to explain to the casual viewer exactly who is riding what, and why.

How many categories are there exactly in MotoGP? Who has more fuel and who doesn’t? And who loses what privileges if they win or podium? To clear up some of the confusion, here is our simple guide to the categories in MotoGP.

There are two categories of bike entered into MotoGP:

Open

Factory Option

All MotoGP bikes, Open or Factory Option, are 1000cc four strokes with a maximum capacity of 1000cc, a maximum bore of 81mm, and a minimum weight of 160kg. They all use the standard Magneti Marelli ECU* and datalogger.

They all have a choice of 2 different compounds of tires at each race. Each team has to decided whether to enter as Open or Factory Option team before the start of the season (28th February). Once the season is underway, they cannot switch until the following season.

The differences between the two classes are as follows:

Open

ECU Software – All Open entries must use the champioinship software written by Magneti Marelli and controlled and supplied by Dorna

Fuel – Open entries are allowed 24 liters of fuel for the race. Most teams don’t need that much fuel, and have 22 or 23 liter fuel tanks fitted.

Engines – Open entries may use up to 12 engines for the entire season

Engine development – Open entries can modify the design of the engine between sealed engines. They cannot open the seals and change an engine once it has been used, but if a part of an engine needs to be redesigned for more performance, they can introduce that modification in the next engine used. In other words, engine #2 can be different in design to engine #3, and engine #5 can be different to engine #7.

Testing – Each rider has an allowance of 120 tires for testing purposes. Open teams can organize tests at any track, with any rider, and test until they run out of tires.

Tire allocation – Bridgestone bring three different specifications of tire to each circuit. The Open teams can use the softest and the medium specification tire.

The Open entries will run under these same rules throughout the 2014 season. No changes will be made based on their results. They keep the same fuel, tires and engines whether they win, podium or finish 23rd.

Factory Option

ECU Software – Factory Option entries are free to use any software they like. In practice, this means the ECU software written and developed by the manufacturers, which is much more sophisticated than the championship software.

Fuel – For 2014, Factory Option entries are allowed to use 20 liters of fuel for the race. This is one liter less than in 2013.

Engines – Factory Option entries may use only 5 engines for the entire season.

Engine development – The design of engines for Factory Option entries is fixed for the entire season. The first engine used in FP1 at Qatar must be identical in specification in every way to the last engine used at the race in Valencia.

Testing – Factory Option riders can only test at the official tests at Jerez, Barcelona and Brno, and at one other designated test circuit. Test riders can use the 120 test tires allocated to each Factory Option rider to test developments.

Tire allocation – Of the three different specifications which Bridgestone bring to each track, the Factory Option teams can use the medium and the hard specification.

The change made to the rules on 18th March gave manufacturers which did not win a race in 2013 and manufacturers which are new entrants some special concessions. These concessions only apply to Ducati and to Suzuki, once Suzuki join the championship in 2015. Some of those concessions will be lost if they start to achieve wins or podiums.

Ducati / Suzuki

ECU Software – Ducati is free to use any software they like. In practice, this means their own ECU software.

Fuel – Ducati is allowed up to 24 liters of fuel for the race. It is unlikely they will use all 24 liters, 22 or 23 liters is more likely.

Engines – Ducati may use up to 12 engines for the entire season

Engine development – Ducati can modify the design of the engine between sealed engines. The rule is the same as the Open entries. This allows Ducati (and Suzuki, in 2015) to develop their engines.

Testing – Ducati has the same testing privileges as the Open entries. This is to allow them to test their developments with the factory riders, who can push the bike harder than test riders.

Tire allocation – Ducati will start 2014 with the same tire allocation as the Open entries, the soft and medium specification tires.

If any Ducati rider wins a race in 2014 or 2015, or if they accumulate 2 second places or 3 third places between them, then their fuel allowance will be cut from 24 liters to 22 liters. If they rack up 3 wins between them, then they will also lose the softer tire, and use the same tire allocation as the other Factory Option manufacturers (i.e. medium and hard specifications).

Finally, a list of who is competing under which set of rules, and what bikes they are racing.

Riders competing as Open entries

No.

Rider

Bike

9

Danilo Petrucci

Aprilia ART

5

Colin Edwards

Forward Yamaha M1

41

Aleix Espargaro

Forward Yamaha M1

7

Hiroshi Aoyama

Honda RCV1000R

17

Karel Abraham

Honda RCV1000R

45

Scott Redding

Honda RCV1000R

69

Nicky Hayden

Honda RCV1000R

8

Hector Barbera

Kawasaki

63

Mike Di Meglio

Kawasaki

23

Broc Parkes

PBM

70

Michael Laverty

PBM

Riders competing as Factory Option entries

No.

Rider

Bike

4

Andrea Dovizioso

Ducati GP14

29

Andrea Iannone

Ducati GP14

35

Cal Crutchlow

Ducati GP14

68

Yonny Hernandez

Ducati GP13

6

Stefan Bradl

Honda RC213V

19

Alvaro Bautista

Honda RC213V

26

Dani Pedrosa

Honda RC213V

93

Marc Marquez

Honda RC213V

38

Bradley Smith

Yamaha M1

44

Pol Espargaro

Yamaha M1

46

Valentino Rossi

Yamaha M1

99

Jorge Lorenzo

Yamaha M1

* An ECU, or Electronic Control Unit, is just a specialized computer for running an engine. It collects data inputs (throttle position, engine revs, bike speed, and 80 or 90 more), and is able to send signals to the ignition, fuel injectors, and throttle butterflies, controlling sparks, fuel, and airflow.

The decisions on how much fuel to inject and when to ignite is controlled by the software loaded on the ECU, in the same way that Microsoft Windows or Mac OSX is loaded on a computer. The Magneti Marelli championship software controls fuel injection and ignition differently to the software which Honda, Yamaha or Ducati use.

One of MotoGP's most respected journalists, David Emmett is the proprietor of the esteemed MotoMatters. We are very grateful to republish David's work here on A&R...though dread the day we ever again get in a car with him.